1. Field of the Invention
The present technology relates to a vehicle control system.
2. Discussion of the Background
In existing vehicles capable of traveling using only the driving force of an electric motor (such as hybrid motor vehicles), if, for example, the vehicles do not start moving on an uphill although the accelerator pedal is ON, that is, if the vehicles enter a stall mode, an electric current may continuously flow in a particular one of a plurality of switching elements of an inverter. Thus, the risk of overheat of the switching element increases. Accordingly, the following technique has been developed (refer to, for example, Japanese Unexamined Patent Application Publication No. 2009-232485). That is, the temperature of the switching element is detected. If the temperature of the switching element is higher than or equal to a threshold value, the driving force of the electric motor is replaced by a mechanical braking force of a brake system. In this way, the temperature of the switching element can be decreased. Thus, failure or malfunction of the inverter can be prevented. In addition, the vehicle can be prevented from rolling backward on the uphill.
For hybrid vehicles having front wheels driven by an internal-combustion engine and rear wheels driven by an electric motor, the following technique has been developed (refer to, for example, Japanese Patent No. 3923451). That is, if the rear wheels rotate in an opposite direction, a mechanical braking force is generated using a brake system in order to reduce a thermal load imposed on the electric motor. In addition, the driving force of the internal-combustion engine is reduced, and the vehicle is stopped.